Ion exchange resins are used in a large range of applications for preferentially removing selected ions from solution. Typically, a solution is passed into contact with the ion exchange resin selected for a particular ion until the resin is loaded with the particular ion to a desired level.
The ion exchange resin is then subjected to an elution process with an elutant such as acid or ammonia to release the desired ion from the resin and present it in concentrated form in the eluted solution.
In large scale operations such as are found in the mining industry, particularly in relation to the mining of gold, ion exchange resins have been used to preferentially separate gold from a gold bearing solution. This approach is effective in certain types of mining operations. However, given the large scale of mining operations, the quantities of resin involved and the various processing steps, the construction of sophisticated apparatus for handling the various aspects of processing can be quite costly and the efficiencies achievable are not always optimal.
In a typical construction, a number of columns containing resin may be arranged on a carousel with a proportion (eg. half) of the columns being arranged so as to receive a feed of gold bearing solution to trickle down through the resin in the column. The remainder of the columns are at the same time subjected to elution to strip gold from the loaded resin contained in the columns. After the first group of columns has been sufficiently charged with gold, the carousel rotates so as to present the columns containing stripped ion exchange resin to the gold bearing liquid flow whilst at the same time presenting the now gold bearing resin to the stages of the elution process.
The complexity effectiveness and cost of this type of operation is such that there is scope for improvement in different aspects of the process.
Thus, the present invention seeks to provide an alternative process which does not require the use of a carousel.